* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
}

body {
    background: #334155;
    color: #fff;
}

.container {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.container h1 {
    margin-bottom: 20px 0 40px 0;
    text-decoration: underline;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(3, minmax(120px, 1fr));
}

.cell {
    border: 2px solid #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    font-size: 60px;
    font-weight: 600;
    height: 120px;
    cursor: pointer;
}


/*.cell:nth-child(1) {
border-top: none;

}
*/

.cell:first-child,
.cell:nth-child(2),
.cell:nth-child(3) {
    border-top: none;
}

.cell:nth-child(3),
.cell:nth-child(6),
.cell:nth-child(9) {
    border-right: none;
}


/*
pu value n = 1,2,3
.cell:nth-child(3n) {
    border-right: none;
}
*/

.cell:nth-child(1),
.cell:nth-child(4),
.cell:nth-child(7) {
    border-left: none;
}


/*
pu value n = 1,2,3
.cell:nth-child(3n+1) {
    border-left: none;
}
*/

.cell:nth-child(7),
.cell:nth-child(8),
.cell:nth-child(9) {
    border-bottom: none;
}


/*
pu value n = 1,2,3
.cell:nth-child(n+7) {
    border-left: none;
}
*/

.gameplayers {
    display: flex;
    justify-content: space-between;
    margin-top: 30px;
}

.player {
    margin-inline: 18px;
    font-size: 24px;
    font-weight: 600;
}

.restartbtn {
    border: none;
    background: #5f5fc4;
    color: #fff;
    font-size: 22px;
    font-weight: 700;
    margin-block: 18px;
    padding: 10px 30px;
    border-radius: 4px;
    cursor: pointer;
}

.restartbtn:hover {
    background: #7272e1;
}

.cell.disabled {
    background: #8c8c8c;
}

.alertbox {
    position: absolute;
    top: 0;
    background-color: #dfdfdf;
    color: #4d4b51;
    width: 100%;
    padding: 8px 12px;
    font-size: 20px;
    font-weight: 600;
    height: 40px;
    display: none;
}

.player1 {
    margin-right: 20px;
}

@media screen and (max-width: 550px) {
    .game-board {
        grid-template-columns: repeat(3, minmax(90px, 1fr));
    }
    .cell {
        height: 90px;
        font-size: 50px;
    }
    .container h1 {
        font-size: 24px;
    }
}